The commission is hereby authorized to provide by resolution at one time or from time to time for the issuance of turnpike revenue bonds of the Commonwealth for the purpose of paying the cost as hereinabove defined of the turnpike, which resolution shall recite an estimate of such cost. The principal and interest of such bonds shall be payable solely from the special fund herein provided for such payment. The bonds shall be dated, shall bear interest at such rate or rates, not exceeding six per centum per annum, payable semiannually, shall mature at such time or times, not exceeding forty years from their date or dates, as may be determined by the commission and may be made redeemable before maturity at the option of the commission at such price or prices and under such terms and conditions as may be fixed by the commission prior to the issuance of the bonds: Provided, however, That the amount of premium on any bonds shall not cause the yield to be more than six per centum per annum from the date of such bonds to the date of their redemption. The bonds may be issued in series with varying provisions as to rates of interest, maturity and other provisions not inconsistent with this act, but all bonds of whatever series shall share ratably in the tolls hereinafter pledged as security therefor. The principal and interest of such bonds may be made payable in any lawful medium. The commission shall determine the form of bonds, including any interest coupons to be attached thereto, and shall fix the denomination or denominations of the bonds and the place or places of payment of principal and interest thereof which may be at any bank or trust company within or without the Commonwealth. The bonds shall be signed by the Governor and by the chairman of the commission, and the official seal of the commission shall be affixed thereto and attested by the secretary and treasurer of the commission, and any coupons attached thereto shall bear the facsimile signature of the chairman of the commission. In case any officer whose signature shall appear on any bonds or coupons shall cease to be such officer before the delivery of such bonds such signature shall nevertheless be valid and sufficient for all purposes the same as if he had remained in office until such delivery. All turnpike revenue bonds issued under the provisions of this act shall have and are hereby declared to have all the qualities and incidents of negotiable instruments under the negotiable instruments law of the Commonwealth. The bonds may be issued in coupon or in registered form, or both, as the commission may determine, and provision may be made for the registration of any coupon bond as to principal alone and also as to both principal and interest, and registered and coupon bonds shall be interchangeable. The commission may sell such bonds in such manner and for such price as it may determine to be for the best interest of the Commonwealth, but no such sale shall be made at a price so low as to require the payment of interest on the money received therefor at more than six per centum per annum computed with relation to the absolute maturity of the bonds in accordance with standard tables of bond values. The proceeds of such bonds shall be used solely for the payment of the cost of the turnpike and shall be disbursed upon requisition of the chairman of the commission under such restrictions, if any, as the resolution authorizing the issuance of the bonds or the trust indenture hereinafter mentioned may provide. If the proceeds of such bonds by error of calculation or otherwise shall be less than the cost of the turnpike, additional bonds may in like manner be issued to provide the amount of such deficit and, unless otherwise provided in the resolution authorizing the issuance of the bonds or in the trust indenture, shall be deemed to be of the same issue and shall be entitled to payment from the same fund without preference or priority of the bonds first issued. If the proceeds of the bonds shall exceed the cost of the turnpike the surplus shall be paid into the fund hereinafter provided for the payment of principal and interest of such bonds. Prior to the preparation of definitive bonds the commission may under like restrictions issue temporary bonds, with or without coupons, exchangeable for definitive bonds upon the issuance of the latter. The commission may also provide for the replacement of any bond which shall become mutilated or be destroyed or lost. Such turnpike revenue bonds may be issued without any other proceedings or the happening of any other conditions or things than those proceedings, conditions and things which are specified and required by this act.

Such bonds are hereby made securities in which all state and municipal officers and administrative departments, boards and commissions of the Commonwealth, all banks, bankers, savings banks, trust companies, saving and loan associations, investment companies and other persons carrying on a banking business, all insurance companies, insurance associations and other persons carrying on an insurance business, and all administrators, executors, guardians, trustees and other fiduciaries, and all other persons whatsoever who now or may hereafter be authorized to invest in bonds or other obligations of the Commonwealth may properly and legally invest any funds including capital belonging to them or within their control, and said bonds or other securities or obligations are hereby made securities which may properly and legally be deposited with and received by any state or municipal officers or agency of the Commonwealth for any purpose for which the deposit of bonds or other obligations of the Commonwealth is now or may hereafter be authorized by law.